Thomas Segismont

In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the PostgreSQL message decoder reads the 4-byte message length field from the PostgreSQL wire protocol without any maximum validation. A malicious, compromised, or man-in-the-middle PostgreSQL server can send a message header with the length field set to an extremely large value (up to Integer.MAX VALUE), causing the decoder to accumulate subsequent TCP data into a composite buffer without bound, leading to unbounded memory allocation on the client and an out-of-memory crash. This occurs before authentication completes. The impacted component is io.vertx:vertx-pg-client.

In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the MySQL message decoder aggregates inbound multi-packet payloads into a composite direct-memory buffer without any cumulative size limit. A malicious, compromised, or man-in-the-middle MySQL server can send a continuous stream of packets with the maximum payload length (0xFFFFFF), preventing the end-of-message condition from being reached, causing unbounded direct-memory allocation on the client and leading to an out-of-memory crash. This occurs before authentication completes. The impacted component is io.vertx:vertx-mysql-client.

**Name of the Vulnerable Software and Affected Versions** Eclipse Vert.x versions 4.0.0 through 4.5.34 Eclipse Vert.x versions 5.0.0 through 5.0.12 Eclipse Vert.x versions 5.1.0 through 5.1.9 Eclipse Vert.x version 5.2.0 **Description** A scope bypass exists in the `ChainAuthHandler` of Eclipse Vert.x Web when utilized with authentication handlers that require scopes, such as `JWTAuthHandler` or `OAuth2AuthHandler`. If a user is already authenticated by a preceding handler in the request pipeline, the `ChainAuthHandler` skips all scope validation configured through `withScope()` or `withScopes()`, affecting both `any()` and `all()` chain modes. This occurs because the `postAuthentication()` function relies on internal state set during the `authenticate()` phase, which is bypassed for pre-authenticated users. Consequently, a user with a valid token but insufficient scopes can access protected resources, particularly in scenarios with overlapping authentication handlers on nested routes. **Recommendations** Update Eclipse Vert.x versions 4.0.0 through 4.5.34 to a version newer than 4.5.34. Update Eclipse Vert.x versions 5.0.0 through 5.0.12 to a version newer than 5.0.12. Update Eclipse Vert.x versions 5.1.0 through 5.1.9 to a version newer than 5.1.9. Update Eclipse Vert.x version 5.2.0 to a version newer than 5.2.0.